There are many instances where it would be desirable for delivering a fluid to a remote site by means of a remote control unit. There may be a need to regulate levels of inert gases, e.g., nitrogen, argon, in a clean room, or to regulate oxygen flow into an oxygen-rich environment. There may be a need to control the level of toxic fluids, e.g., chlorine, bromine in a tent or other enclosure requiring a germ-free or insect-free environment or to maintain an oxygen-free environment in a room containing combustible materials. One instance of particular note is the delivery of supplemental oxygen to a patient experiencing chronic difficulties in breathing. In some instances, such individuals may suffer from diminished oxygen uptake into the body. For example, the lungs of such individuals are not able to transfer oxygen into the blood stream sufficiently and are aided in doing so by increasing the partial pressure of oxygen in the alveoli. Regardless of the cause of the pulmonary ailments, even a partial disability of the pulmonary system may require enrichment or supplementation of oxygen. In extreme instances, a severely compromised respiratory system may be incapable of supplying the necessary oxygen level for an individual. As a result, supplemental oxygen must be delivered to such an individual to maintain the amount of oxygen at an acceptable level. The supplemental amount needed will vary depending upon the activity level of the patient.
Other examples where it would be useful to provide a controlled delivery of a fluid from a remote site with a remote control device include an instrument driven clean room. When robotics replace the human element in a clean room, it may also allow the replacement of a breathable atmosphere with an atmosphere comprising mostly of inert gases to avoid oxidation of elements sensitive even to atmospheric levels of oxygen, such as semiconductors.
Another example of the need to regulate fluid level or concentration from a remote site is the “tenting” of habitable structures to rid them of germs, insects, vermin or other undesirable elements. To be able to control the level of fluids maintained in a tented environment sufficient to perform the task required without endangering the atmosphere outside the tent is a desirable feature of remote control of fluid inputs.
The industrial applications for the remote control of fluid delivery are seemingly endless. In almost any situation where there is a need to deliver fluid into a room or other controlled area where the health and/or safety of an individual would be compromised by entry into the controlled area, fluid delivery controlled from a remote location is a desirable and preferred alternative. Another example that comes to mind is the delivery of oxygen rich fluids into an area of combustible materials. Another example is the remote delivery of chemicals to treat sewage.
As a result, devices and systems for regulating the remote delivery of fluids are known in the art. For example, in the delivery of supplemental oxygen, a stationary source of oxygen is provided having a tube attached thereto for supplying oxygen to the individual. The source may be a tank reservoir containing pressurized medical quality oxygen. A flow regulator comprising one or more adjustable valves may be provided at the source to control the rate of oxygen flow from the tank through the tube to deliver oxygen to the patient by way of a nasal cannula, breathing mask, or transtracheal oxygen delivery system.
In general, there are two categories of fluid regulation systems, continuous flow and condition-responsive flow. As alluded to above, continuous flow devices and systems are generally set at a flow rate that provides continuous fluid flow to the site, regardless of the immediate need for fluid input. A continuous flow device and system for supplemental oxygen is generally described in U.S. Pat. No. 6,467,505 to Thordarson et al. A drawback associated with a system such as described in the above noted patent is that that the user benefits primarily from the supplemental oxygen during times in the respiratory cycle when the patient is inhaling. At other times, the supplemental oxygen released is of minimal benefit. Thus, when a continuous flow system uses fluid holding tanks of finite volume, such a system requires more frequent refilling and/or changing of the tanks.
In the alternative, condition-responsive systems are employed to extend the time that a system may receive fluid by providing fluid to a system only when the system generates a fluid input signal. For example, a pulsed flow device for oxygen input is described, for example, in U.S. Pat. No. 5,839,464 to Enterline. In the system described, a burst of oxygen is delivered into a patient's nasal passages when a patient begins to inhale. A condition-responsive system operates on pre-set conditions designated by the user. Such pre-set conditions do not allow the flexibility needed in a dynamically changing environment. For example, combustible fuels introduced into an oxygen-rich environment may require multiple and dynamically changing conditions to maintain a safe environment.
When a stationary source of fluid is provided, fluid delivery is initiated by setting a flow rate for a delivery device at the source prior to initiating a sequence of fluid delivery. This is inconvenient when the regulator is out of reach. In addition, when the individual is away from the source, changes in the fluid flow rate cannot be effected. Thus, using this type of stationary fluid delivery system often maintains the fluid flow rate at a higher or lower level than necessary, causing insufficient delivery rates at times and excessive delivery rates at other times.
In some instances, known systems and devices automatically adjust the fluid flow rate to a system. A system responsive to dynamic changes in system requirements includes a fluid source, a means for fluid delivery, a fluid destination point and a valve for delivering fluid from the source to the destination point at multiple flow rates. A sensor is provided at the destination point to sense fluid parameters, e.g., volume, temperature flow rates, and to adjust the valve according to the sensed parameter.
One unavoidable drawback of automatically adjustable devices and systems is that they require a sensor for operability. For example, when the sensor is used to monitor the user's respiration, the sensor may be placed in user's nose, elsewhere in the user's respiratory tract, or on the user's face for detecting the flow of oxygen. As another example, when the sensor is used to monitor the user's physical activity, motion sensor detectors often must be placed on or near regions of the user's body engaging in physical activity. As a further example, when the sensor is used to monitor the user's blood oxygen content, invasive techniques for obtaining blood or for positioning the sensor may be required. The sensors generally represent a source of discomfort or irritation for the user.
Another drawback for such devices and systems is that automatic adjustment mechanisms are often imperfect. Often, the response times associated with such mechanisms are inadequate and result in the delayed adjustment of fluid delivery.
Thus, there is a need in the art to overcome the shortcomings associated with known fluid regulation technology by providing a system for delivering a fluid that includes a remote control unit to allow a user to adjust the delivery rate of fluid flow.
The remote controlled system of this invention can be applied to both a demand release valve or a continuous flow valve. With the demand valve, it would be used to tell when to start and stop fluid flow. When used with a continuous flow system, it can be used to regulate the flow rate.